Interview questions, puzzles, brain teasers and algorithmic tasks

A short warning: There is a lot more information here than what is just
about Google. Specifically, possibly boring details of plane travel,
Bay area real estate, etc. Feel free to skip sections that don't sound
like they interest you. By skipping sections you'll miss a few little
details that are in the section that might be more interesting, but
that's probably not a big crime.

The Plane flight out
I flew out of RDU airport on a Sunday evening, First Class on America
West airlines, courtesy of Google. The first leg of the trip was on a
brand new Airbus A315. The flight landed in Phoenix Arizona, where it
was 99 degrees. When you stepped out of the cabin, you were basically
hit in the face with the heat. It was a "dry heat", you could say, as
it wasn't sticky, but it sure was hot. I transfered planes to a rather
old Airbus A320. :) The plane I transferred to was old enough to have
ashtrays that had been used. ;) There was some difficulty with the Aux
power units on the plane working, so the AC on the plane wasn't very
comfortable at first. The crew tried 3 times unsuccessfully to start
the plane w/ the Aux power units, and each time, the entire electrical
system would shut down, and the plane would go completely dark. It was
a rather unnerving experience, even with the knowledge that the Aux
power units had nothing to do with keeping the plane in the air after
we took off. After we got off the runway, the plane cooled down and the
rest of the flight was rather uneventful.

The hotel
Upon landing at SFO, I took the train over to the rental car location,
and picked up my rental from Budget, also courtesy of Google. I then
drove down US101 to CA85, then to El Camino Real, where the hotel I
would spend the next two nights in was located. I got checked in by
11:30 and went up to look around. The place was very unusual in a lot
of respects. It definitely had style, everything was decorated with
paintings and artwork by 20s and 30s Russian artists (according to one
sign), but the whole place had a very "square retro" feel to it. There
was no overhead lighting in the room, just lots of lamps attached to
various bits and pieces, including the headboard, the desk, etc. They
were all of a similar style, with highly conical frosted shades, that
were tapered unevenly at the end (i.e. cut through the cone at an
angle). They were all controlled by local dimmers on the lamp bases,
and made for an interestingly lit, yet dim, room. There was a desk with
a very comfy Suede covered desk chair, and a squared off retro living
room chair with a round green leather ottoman reminiscent of ones my
parents had when I was a child. The sink bears mentioning as well. It
was an above counter sink, with a really cool design, and a faucet that
stuck up high enough to be able to pour water into the above-counter
basin. This had the interesting effect of reducing the counter space
consumed by the sink, as where it met the counter was farther down the
taper of the sink, so in a home environment you could actually put
things "under" the lip of the sink without problem. I eventually got to
sleep by 12:15 or so. As a reminder, that's 3:15am according to my
biological clock at he time - a rather long day. :)

Apartments
I woke up the next morning, got a shave and shower, and planned a short
trip up to Google HQ and past the one possible apartment near there.
This trip gave me a good feel for how long it would take to get to
Google for the interview, as well as a first look around their campus.
It took about 7 mins to drive from the hotel up to Google, and on the
way back I got my first look at apartment living in the Bay area. The
complex was nestled in the back of a residential area, and looked a lot
like all of the other houses in the area. The units were single floor,
and grouped in sets of maybe 4 to 6 at most. The all had a nice
pleasing green color, that went well with the foliage surrounding them.
The looked a bit older than I might have liked, but not terribly so. I
didn't notice it at first as an apartment complex, it took a bit to
"find" it even though I was right out in front of it. After that, I
headed back to the hotel to plan a longer route to look at some other
various possibilities for apartments in Mountain View. I planned out a
big circle, going north on 85 to US101, then down the San Tomas
expressway, back down across El Camino Real, then down to Cupertino to
check out one place down there, then back up to El Camino Real and the
Hotel.

Silicon Valley
The bizarre and wonderful thing about this trip was not the various
apartment complexes I saw, although I'll touch on that in a minute. The
startling thing was all of the businesses I passed. Places like NVidia,
Sun Microsystems, Canon, Hitachi, Network Appliance, Oracle, Microsoft,
Apple, and I'm sure dozens of others that I've since forgotten about or
didn't even notice. This really brought home one of the key things
about the trip. When I moved from Greensboro to Raleigh, I found this
thriving flourishing Linux community, and hundreds of wonderful people
who shared my goals and interests, and a thriving business environment
for the type of work I like to do. Driving around the bay area made me
realize that moving from Raleigh to there, would be just like moving
from Greensboro to Raleigh, up an order of magnitude. This change in
environment continues in my mind as one of the primary advantages to
moving to the Bay area.

As for the Apartments, there were numerous things I saw, based on
somewhat unusual criteria Deborah had defined in an online search.
Specifically, places that were cat friendly, that had either washer and
dryer, or washer and dryer hookups. So, needless to say, it's possible
that what I saw was a bit skewed, but it seemed to be a rather unusual
mix. There were a couple apartment groupings that were relatively
similar to the current place we live, in that they were rather new, and
2-3 story, nicely kept locations. One of the complexes was gray, and
the other was in the apparently more common style of south-western
adobe / orangey-brown. Some were older, and a couple certainly didn't
look like places we wanted to live. Generally though, my impression was
that it'd be quite reasonable to choose one of the places from the list
and we could live comfortably and happily in the rent range of $1400 -
$1800 per month.

The Interview
On the way back around my loop I had Taco Bell (yeah, I know, a rather
uneventful ~$3 lunch even when Google was paying up to $30 / day in
food expenses, silly me). I made it back to the hotel at about the
appointed time (12:30) to change and head over to the interview by
1:15. I erred a bit on the side of caution, and arrived at about
1:00pm. I met Stacie, my recruiter / guide for the next few mins, and
she informed me of some of the details of how the proceedings would go.
I was escorted to a small "interview room", which judging by the signs
on the wall there may have been quite a few of. I sat down with Stacie,
who informed me that I would be meeting with 4 pairs of individuals,
for about an hour each. I met with 3 pairs of tech folks, and one pair
of managers. The tech guys basically grilled me for the entire time on
various tech aspects, ranging from file system internals, to
networking, to service level questions on things like apache, DNS, etc.
Their purpose wasn't just to see what I knew, I think, but also to see
how I reasoned out solutions when they found corners of the *NIX world
that I didn't know cold. Specifically things like the inner workings of
TCP Syn cookies, how EXT2 inodes handle storing filesystem permissions,
data, blocks, etc.

There were also interspersed questions asking "Why do you want to work
for Google", "Why did you want to be a System Administrator, etc". They
also asked a few open ended questions such as, "Are there any questions
we haven't asked you, or is there any aspect of your experience that we
may not have seen that you want to talk about?". There were also
opportunities for me to ask questions of each of the various
interviewer groups. I probably should have taken better advantage of
that, and reversed the question in the form of, "If (or when) you were
in my position, what question would you ask of Google that I might not
have thought to ask?" :) Unfortunately I wasn't the clever on my feet.

After the Interview
After leaving the interview I was so brain-fried that I tried to talk
to Deb on the phone about it while driving, and I couldn't really get
past the physical details. My mind wasn't very good at processing
information after all of that, it had started to shut down. :) I got
back to the hotel and took a nap for an hour or so, and again foolishly
passed up the ability to go out and get food on someone else's nickel.
I suppose I wasn't up to the task, as my mind was still mulling over
the afternoon. I ate a bag of beef jerky that I had brought with me (it
started as a snack, honest...) and vegged on the laptop for a bit, then
fell asleep.

Getting home
I set the alarm back to 7:00am the next morning, and woke up at 7:05,
bizarrely not to the alarm. As I was telling myself that I had to get
up or I'd miss my plane back, the alarm went off at 7:07. I checked the
setting of the alarm again, and it was still set to 7:00. So strange.
*shrug* I got packed up as quickly as possible, woofed down some
breakfast at the hotel's breakfast room, and hit the car. I got into
the car and onto the road about 7:35 or so, and traffic was really
messy. It's disturbing how people are completely unable to merge in the
Bay area. Traffic on US101 would be fine, up until we'd get near an on
ramp, and then it would grind to a halt. It was especially bad as we
went past the enormous and gorgeous Oracle building. Eventually I made
it up to the rental car return around 8:00, got the car dropped off
very quickly (which was a blessing in disguise), and then went up an
elevator, jumped on the train, went down an elevator, over a ways, up
an escalator, etc, etc forever too far. I finally got to the ticket
counter, tried to check my rolling bag, and was told that it was too
late to check baggage for my flight (not surprising, as the wheels up
time was only 25 mins away). I wasn't sure if they'd stop me for my
lock picks, but I stowed them in my laptop bag and went over to
security. They closed the security lane I was put in at first, right in
front of me. I got into the other lane behind two old ladies who were
taking forever, and apparently the security guy took pity on me as he
opened up another lane just to run me through quickly (and turned away
the half dozen people that tried to follow behind me). :) So they
scanned my baggage, and I was off for the dash to the gate. I got there
as the next to last person to get onto the plane, and apologized
profusely to the poor gate agent. :) While working for US Airways I've
heard them chat about how they hate people who show up late, so I
always feel bad.

Anyway, safely aboard, the transition in Phoenix went rather smoothly,
with some time to recharge the laptop and iPod so I'd have time to
continue writing this on the second leg of the flight. I snarfed down a
bratwurst with sauerkraut from one of the airport vendors and I was
good to go for the rest of the afternoon (well, except for the Mrs.
Fields cookie I couldn't resist from the flight attendant). :)

Thoughts on the process / What's next
All in all my confidence level of the interview was very high, although
I won't know any details about that until the middle of next week some
time. The process goes something like this. The 8 people I met with
will fill out some form, evaluating me, which seems to involve a score.
They take that information, add it to the previous information of my
resume and my phone interviews, and then it goes before a hiring
committee. That committee meets twice per week, once on Tuesdays and
once on Thursdays. Given the time frame, I probably won't hear back
from them until after next Tuesday. I look forward to hearing how the
salary and other associated stock / bonus benefits stack up, to
determine if it's financially realistic to move to the west coast. That
along with the decision of position (junior, intermediate, senior sys
admin, etc) is all decided by the hiring committee, based on the
available information at hand. At the moment my thinking is that if it
is financially logical, I think I'd like to go for it.

Why Google?
My mother has asked me several times if it's as cool a place to work as
I thought it'd be, and why. I tried to explain to her the quality of
the people I was simply interviewing with, not to mention the rest of
the Google crew that's surely as knowledgeable or more. Regardless of
whether it's reasonable to move out to Mountain View, I'm curious
simply to see what their opinion of me is. Do they think I'm a senior,
intermediate, or junior administrator, compared to their ranks? :) I
suppose that's just my ego talking.

The Google Campus (aka The GooglePlex)
In addition to the cool people, there's the whole atmosphere of Silicon
Valley, which I babbled on before, and of course the amazingly cool
GooglePlex. There were actually 6 people playing volleyball on the sand
volleyball court when i arrived for my interview at 1:00. There are
fridges full of drinks as well as numerous snacks, etc in the kitchens
which are scattered around all over the place. True to what I'd read on
the web, they all seemed to be a little different, with slightly
different stuff in various places, but each having the basics (water,
soda, some juice equivalent, etc) covered. The whole complex itself is
architecturally interesting, from the floor to ceiling windows on one
side of the building which allows you to look in and see the thriving
workplace and all of the work areas. Speaking of work areas...

There are cube walls, but they're not laid out in the traditional
manner. There are groupings, of what looked like usually 4 people, who
share a mostly open work area in the middle, and are surrounded by nice
cube work which has glass windowing around the top. This would seem to
have the dual benefit of allowing you to see through across the entire
area, while still keeping noise distractions mostly contained. Also by
the whole wall not being clear you wouldn't be distracted by motion
behind your monitor or some such. As for monitors, I saw a lot of LCDs,
and I don't think I saw a single conventional CRT, but I didn't go
walking through cube land too much, and I don't know if the area I was
in (Building 41) was at all representative of where the Admins work.

From the information available, it seems that Google has 11 buildings
in the immediate vicinity, with 4 being on that same lot (not separated
by official roads, just surrounded by the parking lot and internal
sidewalks, etc. There seemed to be internal parking under at least one
of the buildings (43) that I imagine is a perk of some fashion, as
there is also external parking (where I parked) which seemed to be
occupied by some staff. The original building design and layout doesn't
really lend itself to a "guard house" or any kind of entrance control,
so their solution was sort of novel. They erected pylons in front of
one entrance, so that you can't drive a car through it. Then, at the
other entrance, they stationed a guy with a little chair and umbrella
who checks visitors coming in and directs them to the appropriate
place. Presumably this deters the casual walker through. That coupled
with mag-locks on all the doors which require a Google card to be
swiped past to open, presents a fairly secure environment. I didn't
venture to the other buildings, so i can't comment on their setup
personally.

Anyway, I think that about covers the details of my trip. If I get some
frequently asked questions after this, perhaps I'll make an amendment.
:)